Controlling fire ants in your yard

Q: Fire ants are always a problem in my yard. What is the best treatment to keep me bite free all year?

A: The eternal question: how to get rid of fire ants. Did you know that we actually have the Port of Mobile to thank for introducing fire ants to North America? Gotta be famous for something I guess!

Unfortunately, fire ants are never going to be eradicated. The good news is that you can keep their numbers in your lawn and landscape so low that you may very well think you live in a fire ant-free world.

The key is to focus on long-term control, which means killing the queen. This approach will not garner instant gratification, so put your patient pants on. But what this method seems to lack in quickness it makes up for in longevity. The best method for keeping you, your children, grandchildren and pets safe from fire ant stings is called the two-step (kind of like a dance, so it’s fun — right?).

The first step in the two-step method is to use a fire ant bait. Baits are food the foraging worker ants pick up, take back to the colony, digest, feed to other workers and eventually to the queen, thus eliminating the colony. Baits can take four to six weeks to kill a colony, but the effects of wiping out the entire queen and her kingdom last for several months.

Baits are best applied in the spring and early fall; avoid times when it’s too hot and dry or too cold. You have to put the bait out when ants are foraging for food, or it will go rancid and they’ll turn up their noses. A simple gauge is if you are comfortable outside in a T-shirt and shorts or jeans, then fire ants are probably out foraging. To be sure they’ll take the bait, drop a greasy potato chip on the ground, wait 20 to 30 minutes and return to the potato chip to see if ants are on it. If so, you can effectively treat with a bait. Baits can seem expensive, but you are broadcasting a tiny amount over a large area, so a bag may last you two years (four applications) if you store it correctly.

Many products are labeled as bait for homeowner use. Look for products containing hydramethylnon, (S)-methoprene, spinosad or a combination of (S)-methoprene and hydramethylnon. It’s important to look for active ingredients instead of brand names, because sometimes companies change an active ingredient — which may change the effectiveness or use of the product — in a product but keep the same brand name. Very confusing and frustrating!

The Extension System has a great publication that is updated each year with available products. It can be found online at www.aces.edu, or you can swing by your local office and pick up a copy.

The second step of the two-step fire ant dance is individual mound treatments. Remember that baits are going to take a few weeks to fully work, and maybe you have a mound right in the middle of your kids’ football field. That’s where contact insecticides come in handy. There are several products that can be used as mound treatments; please refer to the publication noted above. Some common ingredients are bifenthrin, deltamethrin, beta-cyfluthrin and permethrin.

DO NOT DISTURB the mounds before you apply baits or mound treatments. Baits should not be applied to mounds as this will cause the ants to go on the defensive instead of eating the bait. And NEVER, EVER, EVER use gasoline or diesel to kill ants. Yikes!

Additionally, DIY treatments like club soda and boiling water do not provide effective control of fire ants. These methods may satisfy your need to kill these little devils, and you will see some dead ants, and the mound will likely move, but you haven’t actually killed the queen.

For those advanced dancers in the fire ant game, there is one more step to learn after you have mastered the two-step. That is broadcast contact insecticides, which form a residual barrier of control around your property. But I prefer the two-step, which, when done correctly, provides enough control to keep my yard free of fire ants.

About The Author

Mobile County Master Gardeners are volunteers dedicated to improving quality of life by sharing horticultural knowledge & facilitating community projects. The Alabama Master Gardener Volunteer Program is an educational outreach program provided and administered by the Alabama Cooperative Extension System.